The present invention relates to a closure device for a bottle, and particularly to a closure device of the type which is intended to prevent fraudulent refilling of the bottle.
Bottle closure devices of the type to which the invention particularly relates comprise a pourer body which is anchored onto the bottle, a screw cap for the pourer body attached by means of frangible bridges to a fixed outer body, which latter is also anchored to the bottle, a movable unidirectional valve on the inside of the pourer body, which valve prevents the passage of liquid therethrough into the inside of the bottle when the bottle is in the upright position, and which allows the liquid to flow from the bottle during pouring, when the bottle is tilted and the device on the neck of the bottle is lower than the remainder of the bottle.
In closure devices of this type the unidirectional valve cooperates with a valve seat which is usually formed by a membrane interposed between the pourer body and the upper end of the neck of the bottle.
However, it has been found that it is possible, with the use of suitable tools, to introduce liquid into the interior of a bottle even when such a security device is fitted. For example, by working with a flexible metal wire through the openings in the pourer body it is possible to dislodge the valve from its seat. Alternatively, by immersing a bottle fitted with a security device into a receptacle which contains the liquid with which it is desired to refill the bottle, and by keeping the bottle in a substantially horizontal position, it is possible to dislodge the valve from the valve seat, and the liquid in which the bottle is immersed can then flow into and partially refill the bottle.
Such devices also have a seal to prevent illicit removal of liquid from the bottle, this seal consists of a number of frangible bridges which connect a screw cap to a fixed part consisting either of a flange which is clamped to the bottle, or else of a tubular portion which surrounds the neck of the bottle, and is locked axially to the neck so as to be securely fixed thereto.
Making a screw cap of this type having a part joined to it by frangible bridges is very difficult due to the complexity of the moulds required.